textproduct: Rapid City

KEY MESSAGES

-Scattered showers and storms this afternoon and evening, shifting southeast overnight

-Seasonal and mainly dry the rest of the week

UPDATE

Issued at 947 PM MDT Mon Sep 28 2026

Thunderstorms continue to move across western SD at this hour. A few storms in northwestern SD are on the stronger side and radar analysis indicates they're producing some small hail. With current mesoanalysis depicting 500-1000 J/kg MU CAPE with marginal shear over northwestern SD, these storms should remain subsevere as they move east over the next few hours, though they may produce some gusty winds, hail, and brief heavy rainfall.

Expecting warmer and drier days on tap for Tuesday and Wednesday as heights rise in the wake of the upper wave and quasi-zonal upper level flow establishes itself. Next chances for precip will be on Thursday as a cool front pushes through the region.

DISCUSSION

(This Afternoon Through Sunday) Issued at 1015 AM MDT Mon Sep 28 2026

Deep moisture will shift east today via a northern stream shortwave and associated sfc trough. This will transition the region into WNW flow aloft and allow for occasional cool fronts later in the week. Another monsoon wave will push NE into the region this afternoon and interact with a sfc trough dropping into the region. This will force showers and storms across the FA with the best chances across NW SD late this afternoon and scentral SD overnight. A few stronger storms are possible this afternoon across NW SD where increased flow aloft may allow storms to organize for a bit, supporting gusty winds and small hail. Things will dry out NW-SE into Tue, with lingering shower chances reaming across far eastern scentral SD through Tue morning. Seasonal and dry Tue and Wed. Cool fronts will knock down temps Thur, and again this weekend, with highs in the 60s behind these systems. Some light rain may develop with the NW flow impulses if enough forcing and moisture is realized, but these systems will be mainly dry.

AVIATION

(For the 06Z TAFS Through 06Z Tuesday Night) Issued At 1037 PM MDT Mon Sep 28 2026

VFR conditions are present for WY and most of western SD. South central SD continues to see thunderstorms lingering in the area causing locally strong winds and rain. This may result in areas of IFR for CIGS/VSBY. The storms are expected to move out of the area by Tuesday morning. VFR Conditions area expected through Tuesday.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.